And veteran midfielder Kehl says Arsene Wenger's men are fortunate that their defeat wasn't by a greater margin.

Arsenal never really got into the game, they never really got going, and in the end we scored and deserved to win based on the way we played, explained Kehl, speaking to UEFA's official website. "We were alert, in good form and that caused them a lot of problems

"I never really felt that [it wasn't going to be our day] because they never got a hold in the game. Apart from one minor chance in the first half, Arsenal never really offered much.

"I was very confident after we got the first goal and I knew we'd be going for it again in the second half. We could easily have won three or four-nil."

(Image: Reuters)

Klopp's side have endured a difficult pre-season, with star striker Robert Lewandowski leaving for Bayern Munich and the continuation of injury problems affecting the likes of Marco Reus, Mats Hummels and Ilkay Gundogan.

Throw in a host of new signings - such as Immobile, Adrian Ramos, Shinji Kagawa and Matthias Ginter - and Dortmund are in the middle of a considerable period of change, but Klopp was left delighted with how his new-look side performed.

"It was a great performance from my team, it was really strong," said the Dortmund chief. "We were brave, we were fast and we had everything we needed to win this game.

"We wanted to play pressing football and we did it in a perfect way. That's the kind of football I really love. We have been very aggressive and purposeful. It was a fantastic start to the Champions League."